Subclass
Archaeogastropoda Thiele, 1925
List of species
1. Gotlandiella contraria (Lindström, 1884) | Sheinwoodian
3. Pernericirrus lindstroemi Frýda, Ebbestad et Frýdová, 2018 | Ludfordian
Klassificering
| Organism group | Biota |
| Kingdom | Animalia |
| Phylum | Mollusca |
| Class | Gastropoda |
| Subclass | Archaeobranchia |
| Archaeogastropoda | |
| Superfamily | Porcelloidea |
| Subclass | Eogastropoda |
| Neritimorpha | |
| Orthogastropoda | |
| Prosobranchia | |
| Streptoneura | |
| Order | Bellerophontida |
| Heterostropha | |
| Superfamily | Patelloidea |
| Genus | Semizona |